(1) Field of the Invention
The present invention relates to a method for cutting a protective tape applied on the surface of a semiconductor wafer that has been subjected to surface treatment, along with the periphery of the wafer, and relates to an apparatus for cutting the protective tape.
(2) Description of the Related Art
For example, JP-A No. 2004-25438 discloses a following method as a method for cutting a protective tape applied on the surface of a semiconductor wafer (hereinafter, referred to as “wafer” for short).
A protective tape is supplied on the surface of a wafer mounted and held on a chuck table, and then the protective tape is applied on the surface of the wafer by rotative travel of an application roller. Subsequently, the protective tape having a cutter blade stuck thereinto is rotated by rotation of the table (or the cutter blade is traveled), and thereby the cutter blade is rotated and traveled along with the periphery of the wafer. As a result, the protective tape is cut along with the periphery of the wafer.
In the above-described method, the protective tape projected around the wafer is held by applying to the chuck table, and the cutter blade is traveled in a condition that the cutter blade is stuck into the protective tape in the outer peripheral part of the wafer. However, the part of the protective tape projected around the wafer fails to give a stable degree of stretch. That is, cutting at a part having a weaker stretch of the protective tape may give wrinkles and wavy shape, and poor finish of the cut edge of the protective tape, leading to a defect of cutting resulting from disagreement of a starting position and an end position of cutting.
In the tape applying process, the protective tape is stretched in a comparatively stable condition in forward and backward directions of the travel of the application roller. However, in a transverse direction perpendicularly intersecting to the travel of an application roller, there may be shown a tendency of giving a weaker stretch. Therefore, poor finish easily occurs on the cut edge of the protective tape.
In order to cancel such defect, there may be introduced a tensioning device such as compulsory stretching in an outside direction by pinching with a clamp, etc. of the protective tape projecting around the semiconductor wafer. However, in this case, it is necessary to give a width larger than the chuck table to the protective tape in order to provide a part to be pinched of the protective tape. Therefore, the method possibly gives more amount of waste of the protective tape after cutting process, resulting in a disadvantage of higher running costs.